1. Field of the Invention
The present invention relates to a pouch capable of storing a fluid content such as liquid, viscous fluid or powder, and particularly to a discharge-improved pouch provided with a pouring portion having a narrow width in which the pouring portion is improved in expanding ability and configuration-keeping ability, which is preferably applicable to, for example, a pouch for refilling its content into a refill container.
The present invention further relates to a method of producing a film to be used as material forming the above mentioned pouch.
The present invention still further relates to an easy open pouch which is provided with an improved half-cut line as an opening aid to facilitate opening of the pouch, and particularly to an easy open pouch which is facilitated in opening to such an extent that the pouch is easily torn along the half-cut line when an opening operation, and in addition improved in safety of storage to such an extent that it hardly causes spontaneous tearing on the ordinary handling such as a manufacturing process or a transporting or distributing operation.
2. Description of the Related Art
As a pouch for refill which stores and seals up a fluid content such as liquid, a self-standing pouch incorporating with features of a three-dimensional container as well as self-standing ability has been conventionally used, and various technical efforts are adapted to the pouch in order to pour a content from the opened pouch into another container without spill. For example, an opening is made by cutting out only a corner of the pouch, and an upper portion of the pouch is not entirely cut out. Alternatively, a narrow pouring portion is formed at one position of the upper portion of the pouch, or a separately formed pouring parts such as a plastic mold product is mounted at one position of the upper portion of the pouch.
The manner to cut out the corner of the pouch is easy, but it is difficult for this manner to control pouring direction of the content. In particular, when the content is poured into a container having a small opening such as tapered bottle, an opening of the pouch which is small and flexible is liable to get off the aimed opening of the container during a course of pouring to spill the content out, thereby causing problems in easiness and safety of pouring.
As to the other manner in which a separately formed pouring parts such as a plastic mold product is mounted at one position of the upper portion of the pouch, this manner needs many steps to produce the pouch, and also causes high cost of the pouring parts it self. In addition, since the pouch provided with the separately formed pouring parts is relatively thick, cost for storing or transporting gets expensive. Further, when the content is filled into such a pouch, number of empty pouches to be stacked in a feeder of a filling machine is reduced because of a large thickness of the pouch, and an operator has to frequently supply them into the feeder. Accordingly, this manner causes problems of a large cost and a complicated process.
If the rest in which a narrow pouring portion is formed at one position of the upper portion of the pouch is adapted, it is possible to expect a certain improvements in handling and safety of pouring. However, when the pouring portion formed in such a manner is torn and opened, the thus formed opening of the pouring portion is not easily expanded, and flow of pouring is not steady. In particular, when an amount of the remaining content gets small, the opening of the pouring portion is liable to spontaneously close, and if the pouch is pushed in this condition in order to push out the content, the content may flush and spill out. Accordingly, Even this manner also causes the problems in easiness and safety of pouring operation.
On the other hand, as an easy open pouch, there has been conventionally known a pouch in which a notch having an optional shape is formed at an end portion of an opening position. The notch serves as a start point of tearing to facilitate opening of the pouch. However, since the notch can not control tearing to be developed in a constant direction, it is difficult to tear the pouch along a cut line indicating desired direction only by the notch.
In order to solve this problem, for example, use of the notch is combined with a manner in which the pouch is formed from a lamination film having an intermediate layer made of an uniaxial oriented film, an oriented direction of which is aligned with a direction of the cut line (a tearing direction), or a manner in which half-cut line is formed along the cut line.
However, the manner using the uniaxial oriented film causes an expensive cost of a material. Besides, when the cut line is set inclined with respect to an axis of the pouch, it is difficult to align the oriented direction of the film with the cut line.
As to the other manner forming the half cut, since irradiation of a laser beam is available to carry out this manner, an initial cost of a laser machine is expensive but a running cost is cheap, and it is easy to form a half-cut line of any direction, thereby providing advances in those points.
However, an opening position extends from a seal portion present at one side of the pouch to the other seal portion present at an opposite side of the pouch, and a middle of the opening position is non seal portion corresponding to a storing space. Therefore, when the half-cut line is formed at such an opening position, a tearing direction is made steady so as to be torn along the half-cut line, but a tear strength at the seal portion becomes larger than that at the non seal portion as the middle portion, thereby requiring a strong force at beginning of tear.
To the contrary, when the half-cut line is made deep by increasing a power of the laser beam, a tear strength at the seal portion is reduced and tearing is made easy, but a tear strength at the non seal portion as the middle portion is also reduced and gets excessively weak. Accordingly, such a pouch is liable to be broken from the half-cut line by some impact, thereby causing a problem in safety.
This invention has been achieved in order to the above described problems, and a first object of this invention is to provide a pouch, particularly a pouch for refill, in which it is not necessary for production of the pouch to separately form a molded poring parts, and it is possible to produce the pouch at a good productivity as well as a low cost through a process similar to that applicable to an ordinary pouch, and when an end portion of a pouring portion formed at a corner of an upper portion of the pouch is cut out, thus formed opening of the pouring portion easily expands and keeps its configuration, and when a content is poured out, the opening of the pouring portion is prevented from spontaneously closing, and it is possible that the content of the pouch is safely and easily poured into a bottle having even a small opening until pouring is completely finished.
A second object of this invention is to provide a method of producing a film to be converted into the pouch concerned with the first object.
A third object of this invention is to provide an easy open pouch excellent in safety and productivity, in which a half-cut line having an improved shape is formed at a tearing position of the pouch, and it is possible to easily tear the pouch along the half-cut line at the time of an opening operation, and breakage or splitting of the half-cut line is not caused on the ordinary operations in a production process or a distribution stage, and the pouch is applicable to various pouches including a flat pouch such as a three-side sealed type or a four-side sealed type, and it is particularly applicable to a pouch liable to get an actual torn direction off the intended cut line, such as the pouch concerned with the first object because of its bulge portion. The bulge portion will be explained herein after.
A first aspect of a first invention to achieve the first object provides a pouch which is formed of a flexible film and comprising wall portions constituting a front and a rear walls and a pouring portion, wherein both sides of the pouring portion is defined by seal portions so as to form a poring channel, and at least one wall portion is partially protruded to an outward direction of the pouch to be provided with a bulge portion having a hollow structure at vicinity of the pouring portion.
In the pouch as designed above, when an upper end of the pouring portion is torn off, the thus opened pouring portion can spontaneously expand to form large opening, and accordingly the pouch is excellent in a configuration-keeping ability of the opening. When the content of the pouch is poured into another container, the opening of the pouring portion is prevented from spontaneously closing, and even a viscous content can be smoothly pored out from the pouring portion, thus making it possible that the content is safely and easily poured into another container until pouring is completely finished.
In a first preferable embodiment concerned with the first aspect of the first invention, the bulge portion has an out line defined by combination of flat faces, and a cross section defined by combination of straight lines when the bulge portion is cut out in parallel with its protrusive direction.
In the present invention, a flat face for the bulge portion means as a face which does not contain a curved line extending in a vertical direction. Therefore, when the bulge portion is defined flat face, a cross section obtained when the bulge portion is cut out in parallel with a protrusive direction of the bulge portion has a shape defined by straight lines, but the other cross section obtained when the bulge portion is cut out in parallel with a horizontal direction of the bulge portion may have a shape containing a curved line or a round part.
In the pouch as designed above, since a linear corner portion is formed at a boundary between the two flat faces, the bulge portion can be improved in resistance to a pushing load and restoration from collapse because of a rib effect of that linear corner portion, thereby more improving the configuration-keeping ability.
In a second preferable embodiment concerned with the first aspect of the first invention, the pouch is a self-standing pouch, and the bulge portion is extending on the wall portion so as to develop an upper part of the bulge portion in an obliquely downward direction from vicinity of the poring portion to a center line with respect to a width direction of the pouch, curve a middle part of the bulge portion to a further downward direction, and develop a lower part of the bulge portion in a vertically downward direction, and width and height of the bulge portion are set so as to have a predetermined size at vicinity of the pouring portion, gradually reduce along the obliquely downward direction, and keep constant from the curved middle part of the bulge portion to a further lower position.
In a third preferable embodiment concerned with the first aspect of the first invention, the pouch is a self-standing pouch, and the pouring portion is disposed at an upper corner of the pouch so as to extend in an obliquely upward direction, and the bulge portion is extending on the wall portion so as to develop in a curved form from vicinity of the pouring portion toward a diagonally lower corner of the pouch, and width of the bulge portion are set so as to have a predetermined size at vicinity of the pouring portion, gradually reduce along the obliquely downward direction, and form a linear rib at a lower part.
In a fourth preferable embodiment concerned with the first aspect of the first invention, the pouch is a self-standing pouch, and the pouring portion is disposed at an upper corner of the pouch so as to extend in an obliquely upward direction, and the bulge portion is extending on the wall portion so as to develop in a curved form from vicinity of the pouring portion toward a diagonally lower corner of the pouch, and width and height of the bulge portion are set so as to have a predetermined size at vicinity of the pouring portion, gradually reduce along the obliquely downward direction, and keep almost constant at a lower part.
In a fifth preferable embodiment concerned with the first aspect of the first invention, the pouch is a self-standing pouch, and the pouring portion is disposed at an upper corner of the pouch so as to extend in an obliquely upward direction, and the bulge portion is extending on the wall portion so as to develop in an obliquely downward direction from vicinity of the pouring portion to vicinity of a center of the pouch or develop in a V-turned form from vicinity of the pouring portion to vicinity of an opposite upper corner of the pouch via vicinity of the center of the pouch, and width and height of the bulge portion are set so as to have a predetermined size at vicinity of the pouring portion, and become small at a further tailing part.
In the pouch according to the second to the fifth preferable embodiments concerned with the first aspect of the first invention, the pouch can be bent to an outward direction of the pouch along the lengthened bulge portion by volume and weight of the content, thereby outward expanding an area lower than the pouring portion as well as the opening and the pouring channel. Accordingly, the content of the pouch can be smoothly flowed to the pouring portion and smoothly poured out from the pouring portion.
Besides, when the bulge portion takes such a V-turned form as in the fifth preferable embodiment, the V-shaped bulge portion is coincide with a bent line which is formed at an upper area of the wall portion by filing, degassing and sealing up the pouch. Accordingly, the V-shaped bulge portion can steady configuration of the pouch and improve an appearance of the pouch. The V-shaped bulge portion is also excellent in a visual balance. Further, when the pouch having the V-shaped bulge portion is opened, the pouch can be bent to an outward direction of the pouch along the V-shaped bulge portion by volume and weight of the content, thereby outward expanding a center area of the pouch as well as the opening and the pouring channel. Accordingly, the content of the pouch can be smoothly flowed to the pouring portion and smoothly poured out from the pouring portion.
A second aspect of the first invention to achieve the first object provides a pouch which is formed of a flexible film and comprises wall portions constituting a front and a rear walls and a pouring portion, wherein both sides of the pouring portion are defined by seal portions so as to form a neck portion, a shoulder portion starting from a lower end of the neck portion, and a poring channel passing through the neck and the shoulder portions, and the pouring portion is provided with a cut line indicating a course for opening of the pouring portion, the cut line passing over a vertex of a vertical angle of an assumed right triangle or a position closer to a center of the pouch than the vertex when the assumed right triangle is drawn by taking a straight line defined by two connection points connecting an inside line of the seal portion of the neck portion and that of the shoulder portion as its base, facing its vertical angle toward an upper end of the pouring portion, and setting its vertex of the vertical angle on an axis of the pouring channel.
When the pouring portion of the pouch is torn off, and the content is poured out from the narrow pouring portion, bent lines (wrinkles) extending toward the upper end of the pouring portion are liable to be formed at both sides of the pouring portion owing to an internal pressure of the content. This bent lines cross over each other to choke an upper part of the pouring portion. In contrast, since the pouch of the second aspect of the first invention provided with a cut line properly positioned, when this pouch is opened, an upper part to cause the choking can be torn off the pouring portion, thus making it possible that the content is safely and easily poured out until pouring is completely finished.
A third aspect of the first invention to achieve the first object provides a pouch which is formed of a flexible film and comprises wall portions constituting a front and a rear walls and a pouring portion, wherein both sides of the pouring portion are defined by seal portions and cut off portions so as to form a neck portion, a shoulder portion starting from a lower end of the neck portion, and a poring channel passing through the neck portion, and the pouring portion is provided with a cut line indicating a course for opening of the pouring portion, and both transit portions transiting from an inside line of the seal portion of the neck portion to that of the shoulder portion are curved, the cut line passing over one point on a trace drawn by a vertex of a vertical angle of an assumed right triangle or a position closer to a center of the pouch than at least one point on the trace when the trace is drawn by taking the assumed right triangle having the base longer than a width of the pouring channel, inserting the vertical angle into the pouring channel from lower side thereof, sliding the assumed right triangle with both sides defining the vertical angle being kept in contact with the both inside lines of the seal portions of the pouring portion.
In the pouch according to the third aspect of the first invention, since the both transit portions transiting from the inside line of the seal portion of the neck portion to that of the shoulder portion, i.e., a base of the pouring channel, are shaped into curved lines, an edge of the pouring channel is very smooth. Accordingly, even if an internal pressure of the content is loaded on this transit portion, it does not cause rupture or stripping of the seal portion, thus preventing breakage of the pouch.
Further, since a position of the cut line is set in the above described manner, a cross point of the bent lines (wrinkles) extending from the base of the pouring portion toward the upper end of the pouring portion is formed on the cut line or at a position upper than the cut line . Accordingly, when the upper portion of the pouring portion is cut out along the cut line, a position upper than the cross point where choking of the pouring portion occurs can be cut off. As the result, the opening can spontaneously expand with an excellent configuration-keeping ability, and the opening can be prevented from spontaneously closing during the pouring action.
In one preferable embodiment concerned with the third aspect of the first invention, the both inside lines of the seal portions defining the neck portion are shaped into upward protrusive arcs respectively so as to taper the pouring channel of the neck portion off to an upper end of the pouring channel.
Such a design is very suitable to a construction of the pouring portion for a liquid content. When angle or direction of the cut line comes near vertical with respect to a widthwise direction of the pouch, an upper side of the neck portion can be made long, thereby facilitating that a pouring direction is controlled downward. On the other hand, when angle or direction of the cut line comes near horizontal, a lower side of the neck portion can be made long, and accordingly the pouring portion can be shaped into a long gutter-like form.
A second invention to achieve the second object provides a method of producing a film for pouch, which comprises steps of: preheating a resin film; subjecting the thus preheated resin film to press molding with the use of a die comprising a cavity piece and a core piece and having a portion corresponding to a shape of a bulge portion to be provided for the resin film; and, cooling the thus press-molded resin film while it is held in the die.
According to this method, sink of molding can be reduced, and even when the bulge portion is formed to such a lamination film as not suitable for being molded, it is possible to form the bulge portion having a shape which is very similar to a desired shape and excellent in its configuration-keeping ability at a good productivity.
A third invention to achieve the third object provides a pouch which is formed of a flexible film and comprising wall portions constituting a front and a rear walls, wherein a half-cut line as an opening aid is provided to a position to be opened of the pouch, the half-cut line being formed so as to have a combination of a deep part and a shallow part and/or a combination of a wide part and a narrow part.
In one preferable embodiment of the third invention, both sides of the pouch are defined by seal portions, and the half-cut line is extending on the wall portion so as to start from the seal portion of one side, traverse a non seal portion as a middle portion and reach the other seal portion of the opposite side, and depth and/or width of the half-cut line is made deep and/or wide at the seal portion from which opening is to be started in comparison with those made at the non seal portion.
When the pouch of the third invention is opened, an opening position of the pouch can be easily and exactly torn along the half-cut line. In addition, the pouch of the third invention is prevented from being ruptured, thus being excellent in safety of storage.